2011-01-16 FPU catch division by zero

There can occure some problems in C onw of them is divison on zero. For this we setup system exception handler or signal handler.  When is division on zero it works.Also for return in main function there is used setjmp and longjmp

void set_exception_handler()
{
	int err;
	fenv.__control_word &= ~FE_ALL_EXCEPT;
	fenv.__cs_selector &= ~FE_ALL_EXCEPT << 7;
	fesetenv( &fenv );	
	
	sa.sa_sigaction = &exception_handler;
	sa.sa_flags = SA_SIGINFO;
	err = sigaction( SIGFPE, &sa, NULL );
	if (err != 0)
		printf("Cannot set FloatingPoint exception handler\n");
	else
		printf("[OK] SIGFPE is set\n");
}

void exception_handler(int i, siginfo_t *s, void *v )
{
	if (s->si_signo == SIGFPE)
	{
		printf("[SIGFPE] SIGFPE Occure\n");
		printf("[SIGFPE] Error number: %d\n", s->si_errno);
		printf("[SIGFPE] Signal code: %d\n", s->si_code);
		switch (s->si_code)
		{
			case FPE_INTDIV:
				printf("[SIGFPE] Divison by 0\n");
				longjmp( jmp , 1 );
				break;
		}
	}
	abort();
}

Compilation is easy:
gcc sigfpe.c -o sigfpe -lm
Now it will no so big problem when some error occur to properly exit or make some checks.